Robert waddell



M mmm /w M ,.5 fm W N. PETERS. PHOTO-LITHOGRAPNER. WASHINGTON. D C.

ROBERT WADDELL, OF ENGLAND.

BALANCING SLIDE-VALVE OF sTEAMp-ENGINES.

Specification of Letters Patent INO. 10,999, dated June 6, 1854.

To all whom t may concern Be it known that I, ROBERT WADDELL, of England, have invented certain new and useful Improvements in `Steam-Engines, more peculiarly adapted to engines used on board ship, some of which, however, may be used with great advantage in various classes of engines.

These improvements relate first to certain contrivances for freeing the various species of slide valve from the pressure of the steam; second, to a method of balancing the valve in such manner that it is neither held against the port when there is a vacuum therein or driven from it whenthere is a pressure of steam in that end of thecylin der to which the port leads.

valve a species of table or support provided with a rim or its equivalent against which l the inside of the valve plays steam tight, a 1

connection being made insome manner `between the chamber thus formed by the valve, the table and the rim and the interior of the steam chest.

The object herein attained is not a new one, as many plans have been contrived `for freeing the back of the valve from the pressure thereon, the usual method being either to `pack the back of the valve to the top of the chest or vice versa, or to make the valve in two pieces one of which fits as a kind of t piston within the other. My plan is, however, entirely different from these, is more` simple, inexpensive, and less liable to get out of order and has the further andlgreat advantage that the valve continually by its own wear grinds the packing tight, for as the valve wears away its own face, or lts` seats, so 1n my plan does 1t wear its own back or the rims `of the table before alluded to. Moreover, by my plan a certain portion ofthe wear of the valve is transferred from its face to its back and the same amount of thetop of the chest against the back of the valve in such manner that said packingv shall isolate from the steam chest a small1 nearly so in area to the steam port. This packing in connection with the back of the valve and the inner surface of the steam chest forms a little chamber which u portion `ofthe back of the valve equal or is opposite one of the ports and connected thereto by means of a pipe or its equivalent. The pressure in this litle chamber will therefore be equal to the pressure in the port, so will the vacuum therein and it is clear that the valve if balanced `in other parts of its length will neither press against the port nor be pushed away from it. l

Having thus essayed to give some idea of the nature of the parts of my invention and set forth some of their more obvious pel culiarities and `advantages I willproceed to p The` nature of the Iirst part of my `.1n- `vention consists in placing within a slide describe by reference to the drawings one form of apparatus embracing them 'all and exhibiting them clearly.

t Figure l of said drawings is a sectional view through the cylinder, valve chest, condenser,fand air pump of a side lever engine. In said view is also shown in elevation the steam pipe and throttle valve. Fig. 2 is a perspective view of the equilibrium table. Fig. 3 is a horizontal view of the freeing valve for 'the condenser, Fig. 4 being a transverse section across the body of a ship, showing portions of the paddle wheels, steam pipes, throttle valve, levers, and small controlling cylinders, one of which in this instance is bolted to each sideof the vessel.

The same letters refer to the same parts in all the figures. Y

The cylinder of the engine is shown at a, with ports b and c, connecting as usual with the steam chest (l. In this chest plays a slide valve c. Within the valve is bolted or otherwise secured to the face of the steam chest the table f, which has all around it a projecting ledge, as g. The top of the table is solid, as shown at It, and its bottom is pierced with several holes or passages j y', which lie directly over the passage for the exhaust at Ze. Steam is admitted to the steam chest through the apertures Z Z, or either of them, and the exhaust is in' any of the ordinary manners connected with the channel way m and the condenser n. `The back of the valve is pierced with one or more passages 0 `o, and its inner face is ground so as to play steam tight upon the ledge g. Upon t-he back of the valve rest the packing pieces 79- p, set up by screws of the fluid with which y is filled. grinding of the inside of the backof the 30 .connected to the lever s. slides in a seat outside the channel way andl closes or opens an aperture which connects said channel way with the outer air. This` valve when the engine is at work and the aperture is shut by it is kept close against its seat by the pressure of the air, there be- `ing a vacuum in the channel Way, and is so' much larger than the aperture that it canl or other appropriate contrivances, 'and so arranged that they inclose on the back of the valves an area equal or nearly so to the ports Z) and c. These inclosures communicate with the ports by means of small passages, clearly shown in the drawings, while the space Q is connected with the rest of the valve chest, or with the condenser, or is open to the air. This valve is purposely drawn in a position where both ports are covered and I will now explain how it is in equilibrium.

There is steam on the upper sidey of the piston and the lower side with the whole interior of the valve is n vacuo. The steam in the chest presses equally in both directions upon the ends of the valve, and also backward and forward and sidewise upon such portions of it as overlap the po-rts. The spacey 1, is filled with steam of the same pressure as that which will fill the upper end of the cylinder, and the-space s is n cacao tothe same extent as the lower end of thecylinder, while the apertures 0 0 connect the two sides of the back of the valve and equalize the pressure that might act 0n either of them, depending upon the tension The valve prevents any leakage past the rim or ledge g, and the valve is on every side perfectly balanced. It is thus balanced in every position that it can assume and needs to move it only sufficient force to overcome the slight friction of the'packing at 79 p. Any vknown species of slide may thus be balanced, all that is necessary being tor change the contour of the table ledge and the packings in such manner that they may perfectly adapt themselves to the form of the slide or valve proper.

In the condenser n, a fioat 1" is attached toone end of a lever s', pivoted at t, whose v other extremity plays freely wit-hin a guide u. To this lever is att-ached by means of. connecting rods and bell cranks or other apj propriate devices aslide or other valve o,v

which when put in motion opens and closes the injection pipe fw, whose mouth is located as usual above the showering plate ai. This valve with all its connections lies inside the condenser, so as to obviate all necessity of.V stufling boxes or similar contrivances which would be needed if the connecting rods, etc., g

. Each of these levers is bent and has applied were located outside thereof.

Another valve y, is by means of a pin e This latter valve be moved through a considerable distance before it commences to open the aperture a. The footvalve is represented at b2, the air pump bucket and valve at b3, and the delivery door at Z2, a port-ion of the hot well and airvessel being shown at b5 b5. Y

The action of this apparatus is as follows As water commences to accumulate' in the bottom of the condenser, the float r', rises and gradually closes the valve o, thus shutting off a portion and finally the whole of the injection water, the valve y, rising at the same time, but not commencing to open the aperture o unt-il the valve U has shut off the injection. The aperture a then commences to open and as soon as it does so air rushes into the condenser, establishes an equilibrium between the condenser andthe outer air and the water in n, runs out into the bottom of'the ship. As the water falls to its proper level, r falls and closes a', while it opens u and the parts again take the position shown in the drawings.

To the extremity of the pin. zv and o-utside of the channel way is attached a rod m connected to a handle'a, by means of. which the lever s can be gent-ly vibratcd, so thta the engineer may assure himself that all the parts are in proper order. By means of this also the valve y can be made to Operate as a snifting valve. y

The opening of o by means ofy will cause a. violent rush of air to the condenser, accompanied with much noise and will'effectually arouse the attention of an engineer who has been heedless of all other warnings as to the condition of his condenser. It is obvio-us also that either valve alone when attached to a ioat will produce a good effect, but the best result will follow when bot-h are applied substantially in the manner described. In Fig. 4, the pistons, cylinders, steam pipes, etc., are purposely represented on a much larger scale than the vessel and the paddles. A sect-ion of the vessel is represented at o o, the lower float boards and wheel arms at p p and the steam pipes at s2 s2. Two small cylinders c c2 are firmly bolted to the sides ofthe vessel. Each of these is provided with an appropriate piston and piston rod, which latter is by means ofa pin connected with a slot in a lever attached to a throttle valve shown in dotted lines.

to its other extremity a weight w. The piston rod 0f c has alsoapplied to it a spring d resting with one extremity against a collar e attached to the piston rod and lat its other against a collar f attached by be wide open.

water outside of the vessel by means of apertures g g2, which can in case of accident to either cylinder or piston be closed by stop valves k h2. Each piston rod is by means of appropriate connecting rods c 792 connected withthe opposite ends of a small lever beam Z and both cylinders are open on their inner ends. Vhen the vessel is on -an even keel and the floats have their proper dip the weights or springs, or bot-h, are so adjusted that the pistons will take the po-sitio-n shown in the drawings, the pressure of the water on one side being balanced by the power of the weights or springs acting upon the piston rods and the throttle valves will y As the water leaves the wheels,'t-he pistons will move outward as the pressure of water thereondecreases, and the throttle valves will commence to close, shutting off steam and slowing down the engines. The contrary effects take place as the wheels become again immersed. In double engine ships it is now usually the practice to connect the engines by means of a center sha-ft, so that the power of `both is applied to either wheel. In such cases it is best to connect the pistons appertaining to c c2 in the inanner described, and for the reason that the two wheels are often when the ship is rolling unequally immersed. In such cases one wheel immerses as the other emerges or nearly so and the steam applied to the engine should be graduated according to their mean dip. The connection shown effectually answers this purpose, as the throttles are thereby moved according to the mean of the pressure on the small pistons. In a single engine ship this connection is also necessary, but in vessels where each engine drives its own wheel the contrary is the case.

This apparatus that is to say the pistons, cylinders, etc., with their attachments to the throttle may be applied advantageously to screw vessels, in which case the cylinder should be located in the `dead wood in the run, so that the pressure of the column of water on the outer side of the piston should be proportional to the immersion of the p screw propeller.

.It is obvious that any train of motions known to mechanics may be used for connecting the pistons with the throttles or for applying the force of weights or springs to thrust the pistons outward and that any known springs may be used for this purpose or any known species of throttle valve be substituted for those shown in the drawings. It is further obvious that any known floats,

valves, or connections may be used in place of those described in the condenser and channel way so long as the valves act as described when operated by the float. It is also clear that the equilibrium table may be used without the packing pieces 70 fp, p p and that the whole of the valve except a surface equal to the area of the portsrwill then be balanced and also that the'equilibrium table may be supported from the valve seat by legs of any kind instead of those represented or that it might be attached to the back of the valve chest by means of rods passing through the slots 0 0 provided such slots were made as long as the travel of the valve.

Having thus described my invention and some of the modifications of which it is susceptible I claim as of my own inventionl. The equilibrium table with its ledges or their equivalents applied to and actingin combination with the valve substantially as v 

